Zinc Finger Protein-Protein Interactions

描述（由申请人提供）：转录因子之间的蛋白-蛋白相互作用在正常和疾病状态下的基因表达调控中起着关键作用。本申请旨在研究由Cys2His2锌指蛋白介导的蛋白-蛋白相互作用，Cys2His2锌指蛋白是人类中最丰富的一类转录因子。特别是，我们正在重点研究在Ikaros转录因子家族成员和相关同源物中发现的二聚化锌指（DZF）结构域。DZF结构域为研究Cys2His2锌指介导的蛋白相互作用提供了一个模型系统。该提案的长期目标是：获得对Cys2His2锌指如何介导与多种不同蛋白质的特异性相互作用的详细生物物理理解；利用这些知识设计策略来加强、破坏或预测这种相互作用；并设计出具有新型相互作用特异性的合成锌指，这些锌指可以作为有用的模块，用于创建具有潜在应用于生物技术和治疗学的人工调节电路。该应用程序的具体目的是：1)使用突变分析，遗传选择方法和分子图形工具定义和建模Ikaros， Pegasus和Hunchback DZF域接口；2)利用x射线晶体学测定二聚体Ikaros、Pegasus和Hunchback DZF结构域蛋白-蛋白复合物的高分辨率结构；3)利用遗传选择鉴定合成的专性异二聚体DZF结构域，并测试DZF结构域作为“相互作用模块”在真核细胞中组装异源蛋白复合物。

DESCRIPTION (provided by applicant): Protein-protein interactions among transcription factors play critical roles in the regulation of gene expression in normal and disease states. This application proposes to study protein-protein interactions mediated by Cys2His2 zinc finger proteins, the most abundant class of transcription factors in humans. In particular, we are focusing our studies on dimerization zinc finger (DZF) domains found in members of the Ikaros family of transcription factors and related homologues. DZF domains provide a model system for studying Cys2His2 zinc finger-mediated protein-protein interactions. The long-term goals of this proposal are: to gain a detailed biophysical understanding of how Cys2His2 zinc fingers mediate specific interactions with a wide variety of different proteins; to utilize this knowledge to devise strategies to enhance, disrupt, or predict such interactions; and to engineer synthetic zinc fingers with novel interaction specificities that could serve as useful modules for creating artificial regulatory circuits with potential applications in biotechnology and therapeutics. The specific aims of this application are: 1) to define and model the Ikaros, Pegasus, and Hunchback DZF domain interfaces using mutational analysis, genetic selection methods, and molecular graphics tools; 2) to determine high-resolution structures of dimeric Ikaros, Pegasus, and Hunchback DZF domain protein-protein complexes using X-ray crystallography; 3) to use genetic selection to identify synthetic, obligate heterodimeric DZF domains and to test the use of DZF domains as "interaction modules" for assembling heterologous protein complexes in eukaryotic cells.